We have been studying the structures of tetrahedral and octahedral manganese (II) complexes using electron paramagnetic resonance (EPR) at a variety of magnetic field strengths. We have found two compounds, MN(4-picoline)4CL12 and Mn(triphenylphosphine oxide)2C12, whose high magnetic field spectra are inconsistent with computer simulations. We believe the discrepancy may be due to a shifting of the resonance frequency of the spectrometer when sweeping the magnetic field through a strong EPR transition. This problem may be alleviated by reducing the sample size or by taking specter without a resonant cavity.